Monday, August 19, 2013

Time for a new antenna

I have been getting the itch to try out a horizontal loop antenna for some time now.  At the recent Salmoncon event, Eldon - WA0UWH put up a 40 metre vertical delta loop that we fed with 450 ohm ladder line.  The results were, in a word, amazing.  The top of the delta was at about 100' with the other two sides hanging downward and joined at the centre by the feed line.  Running Eldon's FT817 at 5 watts, if we could hear it, we could work it.

Wanting to duplicate these kinds of results at home, I am keen to try out a loop, but in my location, I am only able to obtain about 50 feet of elevation.  I am also interested in top band (160 metres) so a bigger loop is in order.  This will require about 514 feet of wire which works out to about 128.5 feet on a side.

Looking at my site, I have four candidate trees for supports that will provide the ability to build a corner-fed trap trapezoid loop.  The proposed site plot looks like this:

The building is oriented the long way north/south and with this orientation of the loop, I would feed it at the lower left (southwest) corner.  Each of the legs is at least 180' long, so there would be plenty of room for a 160 metre loop.  I wish I could get it up higher, but I guess that will have to wait for trees to grow.